PINGUICULA. 171 



to again face the sun. On referring to my notes, I find 

 the mornings of February 28th and March 6th and 14th 

 are the shortest times recorded — only a few minutes' 

 variation in the time. March 6th eighteen flowers had 

 faced the sun at the expiration of an hour and ten min- 

 utes ; thirteen others made but little movement, but 

 these flowers were old, nearly ready to fall. The flower 

 remains on its stem several days ; after it falls the calyx 

 is left surrounding the seed-vessel, but now it no longer 

 follows the sun. The yellow flowers of P. lutea seem 

 to possess this characteristic more strongly than those 

 of P. elatior. 



Thickly scattered over the whole length of the flower 

 stems, the same as on the leaves, are unicellular hairs 

 tipped with secretor}' glands, and all along the stems 

 minute flies are held by the viscid secretion and rapidly 

 consumed. Pinguicula does not capture as large prey 

 as some species of Drosera, but I never found so great 

 a number of flies, even on the thread-like leaves of 

 Drosera filiform is, as I have found on the flower steins 

 of P. lutea and P. elatior ; but I experimented with 

 Drosera filiformis at the North, where these small flies 

 are not so numerous. I cannot see that there is any- 

 thing to attract the flies, unless it should be the bright 

 flowers. Every warm evening myriads of tiny dipter- 

 ous flies of another species are attracted by the light 

 of the lamp, where they scorch their wings and fall 

 to the table, so that every lamp is surrounded by dead 

 and dying victims. In the same way the bright flowers 



